Field of the Invention
The present invention relates to a ground fault detection apparatus, and in particular to a ground fault detection apparatus detecting a ground fault in an ungrounded alternating current (AC) circuit in which a single-phase three-wire AC power source is connected to a load via a first phase wire, a neutral wire, and a second phase wire.
Description of the Background Art
Japanese Patent Laying-Open No. 2012-122986 (Patent Document 1) discloses a ground fault detection apparatus detecting a ground fault in an ungrounded direct current (DC) circuit in which a DC power source is connected to a load via a positive-side DC bus and a negative-side DC bus. The ground fault detection apparatus includes first and second resistive elements having an identical resistance value. One terminals of the first and second resistive elements are connected to the positive-side DC bus and the negative-side DC bus, respectively, and the other terminals thereof are connected to each other. The ground fault detection apparatus further includes a current detector detecting a value of a current flowing between the other terminals of the first and second resistive elements and a ground point, and determines that a ground fault occurs in a case where the value detected by the current detector exceeds a predetermined threshold value.